Generally, mobile or wireless communications networks are made up of a plurality of cells. Each cell provides a radio communications center through which a mobile station establishes a call or other communications session with another mobile station or a terminal connected to either a circuit-switched network (e.g., public-switched telephone network or PSTN) or a packet-switched data network. Typically, each cell includes a radio base station, with each base station coupled to a switching center or controller that controls processing of calls or other communications sessions between or among mobile stations or between mobile stations and terminals connected to a circuit-switched or a packet-switched network.
Various wireless protocols exist for defining communications in a wireless network. One type of protocol is based on the time-division multiple access (TDMA) technology, such as the TIA/EIA-136 standard or the Global System for Mobile (GSM) standard. Another type of protocol for wireless communications is based on the code-division multiple access (CDMA) technology. CDMA is a spread spectrum wireless communications protocol in which transmission is based on the spread spectrum modulation technique to allow many users to have access to the same band of carriers.
Traditionally, wireless networks were designed for carrying circuit-switched voice traffic. However, with the wide availability of the Internet and intranets, packet-switched communications (e.g., web browsing, electronic mail, instant messaging, electronic gaming, and so forth) have become common. As a result, third generation (3G) and beyond wireless technologies are being developed and implemented to provide higher bandwidth and more efficient packet-switched communications (of data as well as voice and other forms of real-time data) over wireless networks.
Packet-switched wireless communications protocols have been developed for a variety of wireless protocols, including both TDMA and CDMA. For example, in the CDMA context, a CDMA 2000 family of standards has been developed that is capable of supporting both traditional circuit-switched traffic as well as packet-switched traffic. On the TDMA side, 3GPP (Third Generation Partnership Project) UMTS (Universal Mobile Telecommunication System) standards have been adopted or are being developed. UMTS is based on the wideband code-division multiple access (W-CDMA) technology. Also, for TDMA, versions of the Enhanced Data Rate for Global Evolution (EDGE) technology are also being developed.
A wireless communications network that is capable of supporting packet services, such as voice-over-Internet Protocol (IP), electronic mail, web browsing, and so forth, includes various components that enable a mobile station to communicate wirelessly over radio frequency (RF) signaling with a packet-switched network, such as the Internet or various private intranets. Potentially, there can be a large volume of traffic that is communicated between a wireless network and the packet-switched network. As a result, resources of the wireless communications network can become highly loaded. In such conditions, the quality of communications can deteriorate, such as by packets being lost or calls being dropped.